Radiators will not bleed

18 Mar 2008
Reaction score
United Kingdom
I have a gravity feed system using a Potterton Profile boiler, I have had no serious issues in the past 5 years I have lived in my house.

My wife accidentally left a bleed valve open on an upstairs radiator last night causing quite some mess as you can imagine. I am now attempting to get the radiators to heat up again but with no success.

We have 6 down stairs rads "2 fed pre pump" and 6 upstairs rads.

The 2 pre pump rads are toasty warm so this suggests the boiler is ok, the pump is defiantly running when the system is fired up but none of the post pump radiators are getting hot.

The upstairs radiators will not bleed, by this I mean I open the bleed valve and within seconds the air stops coming out but no water flows. I have sat with the bleed valve out of a couple of rads for 15-20 mins and no water still.

Any advice or a solution on this one would be welcome.
Sponsored Links
possibly a blocked cold feed, where it joins the system, usually in the airing cupboard near the pump

i came across this last week.air lock in the feed pipe to the rads.
to overcome this( an option) attach garden hose to the mains pressure (cold tap) and other end of the hose to the radiator .best downstairs radiator drain valve connection and open both end slowly until cold water rushes to the system and upto the tank inthe loft.
I have tried this this evening. When I loosen the square head on the drain cock the water pours out from around the thread .....challenging with the fitted carpet! ....how do you stop that so the mains pressure does its job and re-fills the system?
Sponsored Links

1.towels around the valve
2.attach the hose to the drain valve
3.open the valve quickly attach other end of the hose to the tap
3.open tap slowly get someone to hold ends of the pipe
4.in most cases air lock will be pushed in to the tank in less than 1min
If its an airlock turn off all the rads except one of the ones that isnt bleeding, fire the boiler and open the bleed screw..more often than not works,(however you really should finish the bleeding with the pump turned off.

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local